posted by Anonymous
Calculate the mole fraction of acetic acid in vinegar, assuming that vinegar is 5.00% acetic acid(by mass) and that the density of vinegar is 1.05 g/mL
Let's call acetic acid HAc.
5.00% HAc by mass means 5.00 g HAc in 100 g solution.
moles in 5.00 g = 5.00/molar mass HAc. You can do the math.
The 100 g soln is made of 5.00 g HAc 95.0 g H2O. moles H2O in 95.0 g H2O = 95.0/molar mass H2O. You can do the math.
mole fraction HAc = moles HAc/total moles where total moles = moles HAc + moles H2O.
CH3COOH is acetic acid, always remember the formula or it will be wrong
And i don't get the question
The problem is to convert percent by mass to mole fraction.